Snow vehicle

ABSTRACT

A snow vehicle is disclosed comprising a vehicle frame, a propulsion unit coupled to the frame, and at least one front ski steered by a steering mechanism. The front of the vehicle includes a first front suspension and a second front suspension coupled to the ski. The rear suspension includes a bumper assembly preventing bottoming out of the rear suspension. The rear suspension is coupled to the vehicle frame such that the longitudinal spacing between the vehicle frame and rear suspension is adjustably controllable.

BACKGROUND

The present application is a continuation of patent application Ser. No.15/165,862 which is a continuation-in-Part of patent application Ser.Nos. 14/935,224 and 14/935,265, the subject matter of which aredisclosed herein by reference.

BACKGROUND

The present disclosure relates to snow vehicles including snowmobilesand or snow bikes.

Many types of vehicles are configured with tracks to drive in the snow.Regardless of whether the vehicle is a snowmobile or a wheeled vehicleconverted to a tracked vehicle, tracked vehicles typically include adrive shaft mounted to a suspension system that supports the endlesstrack. The drive shaft typically includes drive sprockets that engagethe endless track. Irregularities in the snow and ice covered terraincause the suspension system to move. Shock absorbers are typically usedto absorb the movement of the suspension system. Common suspensionsystems are configured to collapse towards the tracked vehicle whenabsorbing the movement. However, in some situations, the irregularitiesin the terrain cause movement in the suspension away from the trackedvehicle that is not accommodated by the suspension system.

In the case of snow bikes, the front suspension comprises the suspensionof the motorbike or dirt bike, that is, a front shock absorber. In thecase of snowmobiles, the front suspension is typically includes twocontrol arms, also known as double A-arms. However the front snowmobilesuspension can also be a trailing arm suspension. The suspensiondescribed herein would typically supplement any of the front suspensionsdiscussed above, although it could also be the primary suspension.

One such snow vehicle is shown in our U.S. Pat. No. 8,910,738, thesubject matter of which is incorporated herein by reference. This patentdiscloses a conversion of a motorbike into a snow vehicle where themotorbike powertrain is utilized to power the track of the convertedsnow vehicle.

SUMMARY

In a first embodiment, a snow vehicle comprises a vehicle frame; apropulsion unit coupled to the frame; at least one front ski; a steeringmechanism coupled to the frame; a first front suspension coupled to theframe; a second front suspension coupled to the at least one ski; a rearsuspension coupled to the frame, the rear suspension comprising: atleast one slide rail; at least one control arm coupled between the sliderail and the frame; at least linear force element coupled between theslide rail and the frame; and at least one carrier roller coupled to theat least one slide rail and the frame; a bumper assembly preventingbottoming out of the rear suspension; and a drive system comprising adrive track slidably guided by the at least one slide rail and drivablycoupled to the propulsion unit.

In another embodiment, a rear suspension for a snow vehicle, comprisesat least one slide rail; a frame; at least one control arm coupledbetween the slide rail and the frame; at least linear force elementcoupled between the slide rail and the frame; at least one carrierroller coupled to one of the slide rail and the frame; a drive systemcomprising a drive track slidably guided by the at least one slide railand drivably coupled to the propulsion unit; and a bumper assemblycoupled to the rear suspension and positioned to prevent contact of theat least control arm and a remaining portion of the rear suspension.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in relation to the drawing figureswhere:

FIG. 1 is a side view of one of the embodiments of snow vehicle asdisclosed in the present disclosure;

FIG. 2A shows a left front perspective view of the front suspensioncoupled to the snow vehicle;

FIG. 2B is a front suspension similar to that of FIG. 2A showing thefront suspension coupled to a conventional snowmobile;

FIG. 3 is a front left perspective view of the suspension assembly;

FIG. 4 is a rear right perspective view of the suspension assembly ofFIG. 3;

FIG. 5 is a view similar to that of FIG. 3 showing the suspension in anexploded manner;

FIG. 5A is an enlarged portion of the linkage assembly shown in FIG. 5;

FIG. 5B is an enlarged portion of the shock absorber mounting as shownin FIG. 5;

FIG. 6A shows a side view of the front suspension coupled to a ski inthe fully extended position;

FIG. 6B shows the front suspension of FIG. 6a in a full trounceposition;

FIG. 7 shows a front left perspective view of the rear suspension shownin FIG. 1;

FIG. 8 shows a rear right perspective view of the rear suspension shownin FIG. 7;

FIG. 9 shows a left side plan view of the suspension shown in FIG. 7;respectively;

FIG. 10 shows a left side plan view of the suspension shown in FIG. 7;

FIG. 11 shows a front left perspective view of the rear suspension ofFIG. 7 in an exploded manner;

FIG. 12 shows a front left perspective view of an upper frame portion ofthe rear suspension assembly;

FIG. 13 shows a rear right perspective view of the upper frame portionshown in FIG. 12;

FIG. 14 shows a rear suspension coupler coupled to the slide rails;

FIG. 15 shows an enlarged perspective view of the bumper assembly;

FIG. 16 is an exploded view of the bumper assembly of FIG. 15;

FIG. 17 is a cross-sectional view of the bumper assembly shown throughlines 17-17 of FIG. 15;

FIG. 18 shows a side view of the bumper assembly in full extension(dotted lines) and in full trounce (solid lines);

FIG. 19 shows a front left perspective view of a second embodiment ofthe rear suspension;

FIG. 20 shows an enlarged portion of the front of the suspension shownin FIG. 19;

FIG. 21 shows an enlarged view of the chain tensioner located at thefront of the rear suspension assembly of FIG. 19;

FIG. 22 shows an exploded view of the chain tensioner shown in FIG. 21;

FIGS. 23 and 24 show opposite views of the chain tensioner bar;

FIGS. 25A and 25B show extreme positions of the chain tensioner in use;

FIG. 26 shows a front perspective view of the bumper assembly of therear suspension of FIG. 19;

FIG. 27 shows an enlarged view of the mounting of the bumper assembly tothe rear control arm;

FIG. 28 shows an exploded view of the bumper assembly of FIG. 27;

FIG. 29 shows an underside perspective view of the rear control arm;

FIG. 30 shows a side view of the bumper assembly in contact with theslide rail in a trounce position (solid lines) and prior to contact(dotted lines);

FIG. 31 shows a front perspective view of a third embodiment of rearsuspension;

FIG. 32 is an exploded view of the rear suspension of FIG. 31;

FIG. 33 shows an enlarged view of main frame portion of the third rearsuspension;

FIG. 34 shows a rear perspective view of the main frame portion of FIG.33;

FIG. 35 shows a rear perspective view of the suspension assembly coupledto the rear control arm;

FIG. 36 shows a front perspective view of the suspension assembly shownin FIG. 35;

FIG. 36A shows an alternate embodiment of the rear suspension assemblyof FIG. 36;

FIG. 37 shows a rear perspective view of the suspension assembly shownin FIG. 36;

FIG. 38 shows an exploded view of the suspension assembly shown in FIGS.36 and 37;

FIG. 39 shows the suspension assembly of FIGS. 37 and 38 when in anextended position;

FIG. 40 shows the suspension assembly of FIG. 39 when in the trounceposition;

FIG. 41 shows an enlarged front left perspective view of a front end ofFIG. 31;

FIG. 42 shows a partially exploded view of FIG. 41; and

FIG. 43 shows an enlarged front right perspective view of a front end ofFIG. 31.

FIG. 44 shows a right front perspective view of an alternate frontsuspension with two skis and an independent suspension for each ski;

FIG. 45 shows a right rear perspective view of the front suspension ofFIG. 44;

FIG. 46 shows a side perspective view of the front suspension of FIG.44;

FIG. 47 shows an exploded view of the front suspension of FIG. 44;

FIG. 48A is an enlarged portion of the spindle assembly shown in FIG.47;

FIG. 48B is an enlarged portion of the linkage assembly shown in FIG.47;

FIG. 48C is an enlarged portion of the shock absorber mounting as shownin FIG. 47;

FIG. 49 shows a right front perspective view similar to that of FIG. 44with the left ski lifted relative to the right ski;

FIG. 50 shows a right rear perspective view with the left ski liftedrelative to the right ski;

FIG. 51 shows a right side perspective view with the left ski liftedrelative to the right ski;

FIG. 52 shows a left side view with the left ski lifted relative to theright ski;

FIG. 53 shows a right side view with the left ski lifted relative to theright ski;

FIG. 54 shows a rear view with the left ski lifted relative to the rightski to clear an obstacle;

FIG. 55 shows a front view with the left ski lifted relative to theright ski to clear an obstacle; and

FIG. 56 shows a front view with the left ski lifted relative to theright ski to ride on a slope.

DETAILED DESCRIPTION OF THE EMBODIMENTS

With reference first to FIG. 1, a snow vehicle is shown generally at 2as comprised of a motorcycle portion 4 having a propulsion unit 5, whichis shown as a two-cylinder motorcycle engine, a frame 6, an operatorsseat 8, and a steering assembly 10 which includes a front fork 12. Afirst suspension member is shown at 14 as a shock absorber assemblyaxially coupled with the forks 12. A second front suspension assembly isshown at 16 which couples the steering assembly 10 directly to a ski 18.A rear suspension assembly 20 is shown having an upper frame portion 22,slide rails 24, side panels 26, control arms 28, 30, linear forceelements 32 and 34 (shown as shock absorbers) and an endless belt ordrive track 36. With reference still to FIG. 1, the snow vehicle 2includes a foot peg 38 for the rider to position their foot thereonduring a ride.

With reference now to FIGS. 2A and 3-5, the front suspension assembly 16will be described in greater detail. As shown best in FIGS. 3 and 4,front suspension assembly 16 generally includes a spindle body 40, alower linkage portion 42, and a mounting portion 44. As shown best inFIG. 5, spindle portion 40 is generally comprised of two plates 50 and52 where each plate includes a plurality of apertures. Namely, plate 50includes apertures 50 a-50 g together with an enlarged aperture at 50 h.Likewise, plate 52 includes apertures 52 a-52 g and an enlarged apertureat 52 h. Spindle portion 40 also includes a plurality of spacers tospace the plates 50 and 52 apart, namely spacers 54 a, 54 b, 54 c, and54 g. An enlarged spacer is provided at 54 h. It should be noted each ofthe spacers 54 a, 54 b, 54 c, and 54 g are somewhat spool-shaped havingan enlarged head portion 56 at each end as well as threaded openings 58at each end. Enlarged spacer 54 h is embossed at each end to define areduced diameter section 60 defining shoulders 62.

Thus, the spindle portion may be preassembled by placing the reduceddiameter portion 60 of spacer 54 h into respective apertures 50 h and 52h. This positions the reduced diameter portion 60 through thecorresponding apertures 50 h and 52 h as shown in FIGS. 3 and 4. Spacers54 c and 54 g may then be aligned with corresponding apertures 50 c, 52c; and 50 g, 52 g. Fasteners and washers may then be positioned againstplates 50 and 52 to retain the two plates together and coupled to thespacers. Namely, fastener 70 c and washer 72 c may be aligned withaperture 52 c and brought into threaded engagement with threadedaperture 58 of spacer 54 c. Likewise, fasteners 70 g and washers 72 gmay be received through apertures 50 g and 52 g to be received into thethreaded ends 58 of spacer 54 g. The fasteners should be brought intoengagement with the threaded apertures of their corresponding spacersbut not fully torqued down at this position as other spacers andassembly is required within the spindle assembly.

With reference still to FIG. 5, mounting portion 44 is shown includingclamp halves 80, 82; 84, 86. Each of the pairs of clamp halves includessemi-cylindrical openings which may encompass the front forks of themotorcycle frame as described above with reference to FIG. 1. Thus,spacers 54 a and 54 b are now aligned with respective pairs of apertures50 a, 50 b; 52 a and 52 b; and fasteners 70 a and 70 b are receivedthrough their respective apertures as shown in FIG. 5. This bringsfasteners into engagement with the threaded ends 58 of the correspondingspacers 54 a and 54 b to a position where the clamp may be closed.

With reference now to FIG. 5A, the link assembly 42 is shown and will bedescribed in greater detail. As shown best in FIG. 5A, link assembly 42includes front links or control arms 100 and rear links or control arms102. Each control arm 100 includes an upper coupling 100 a and a lowercoupling at 100 b. Likewise, control arms 102 include upper couplings at102 a and lower couplings at 102 b. Each of the upper couplings 100 aand 102 a receive sleeves 104 which are profiled to be received in thecouplings 100 a, 102 a. Spacers 106 and 108 respectively, are theninserted through corresponding couplings 100 a, 102 a and into sleeves104. Likewise, spacer 108 is received into couplings 102 a, and intosleeves 104. Thus, control arms 100 and 102 may be aligned withrespective apertures 50 e, 52 e, and 50 f, 52 f (FIG. 5) and fastened tothe spindle assembly by way of fasteners and washers 70 e, 72 e and 70f, 72 f.

With reference again to FIG. 5A, linkage assembly 42 further includes aknuckle 110 having a front pivot coupling 110 a having an aperture at110 b and a rear pivot coupling 110 c having an aperture 110 d. Sleeves112 may be received in lower couplings 100 b of control arms 100 (in theorientation shown in FIG. 5A) and then couplings 100 b may be receivedin alignment with apertures 110 b whereupon fasteners 114 a and washers114 b may be aligned with threaded apertures 110 b to couple controlarms 100 with the knuckle 110. In a like manner, sleeves 116 may bereceived in lower couplings 102 b (in the orientation shown in FIG. 5A)whereby couplings 102 b and sleeves 116 are received over rear pivotcoupling 110 c and in alignment with threaded apertures 110 d.Thereafter, fasteners 120 a and washers 120 b may be aligned withsleeves 116 to couple alignment arms 102 with knuckle 110.

Finally, with reference to FIG. 5B, linkage 42 further includes a shockabsorber 124 having a lower coupling at aperture 124 a and an uppercoupling at aperture 124 b. Split sleeves 126 include reduced diameterportions 126 a and threaded apertures at 126 b. Split sleeves 126 may bepositioned with reduced diameter portions 126 a in apertures 124 b andthe shock may be coupled to the spindle assembly by way of fasteners 70d and washers 70 e positioned through apertures 50 d (FIG. 5) and intothreaded engagement with threaded apertures 126 b. The lower aperture124 a of shock 124 may then be coupled to bracket arms 102 c as shown inFIG. 5B. Sleeves 130 are positioned with reduced diameter portions 130 awithin the shock aperture 124 a. The sleeves 130 and the shock aperture124 a are then aligned with apertures 102 d whereupon fastener 140 maybe received through sleeves 130, apertures 102 d and receive a fastener142 and lock washer 144. Thus, the entire assembled second suspensionsystem 16 is shown in FIGS. 3 and 4 where knuckle 110 is shown asproviding an aperture 110 e for coupling to ski 18 as shown above inFIG. 2A. That is, ski 18 includes ski rails 18 a whereby a pin 18 b maybe received through the rails and into aperture 110 e for retaining ski18 to the second suspension system 16. Ski 18 could be similar to thatshown in U.S. Pat. No. 8,381,857, the subject matter of which isincorporated herein by reference.

Thus, in operation and with reference to FIGS. 6A and 6B, ski 18 isshown in a fully extended position in FIG. 6A and in a full trounceposition in FIG. 6B. As shown in FIG. 6B, control arms 100 and 102 areshown collapsed with the shock absorber 124 in a stroked position.Advantageously, the ski is lifted up and rearwardly relative to spindleassembly 40. It is lifted upwardly in the sense that it rotated (in theclockwise sense as viewed in FIG. 6B). It is rotated in the range of1-5°. It also moves rearwardly, for example, the position of the pin 18b which couples the ski to knuckle 110 moves rearwardly from thepositions shown in FIG. 6A to the position shown in FIG. 6B. That is,the distance in FIG. 6A between the upper pivot point of front controlarm 100 (about fastener 70 e) is shown as X₁, whereas in FIG. 6b thedistance is shown as X₂, where X₂ is greater than X₁. This provides anenhanced suspension system in that the ski is lifted up and rearward;for example, if the snow bike is going over a rock or log, the ski islifted up and over the log rather than pushing the ski into the log.This movement also reduces the friction between the ski and the snow dueto the lifting of the ski.

It should be understood that the spindle assembly may also be usable ona conventional snow mobile, and as shown in FIG. 2B, spindle 16′ isshown coupled to upper and lower alignment arms or control arms 150,152, where upper control arm 150 is coupled to spindle assembly 16′ byway of a ball joint at 154. Although not shown in FIG. 2B, lower controlarm 152 would also be coupled by way of a ball joint to spindle assembly16′. It should be further understood that spindle assembly 16 or 16′could be adapted for use with a trailing arm type snowmobile suspensionof the type shown in U.S. Pat. No. 6,328,124, the subject matter ofwhich is incorporated herein by reference. A full description of thefront suspension is described in our co-pending patent application Ser.No. 14/935,265, filed Nov. 6, 2015, incorporated herein by reference.

With reference now to FIGS. 7-19, rear suspension 20 will be describedin greater detail. As shown, and in particular with reference to FIGS.9-11, rear suspension 20 includes an upper portion 154, an intermediatesuspension portion 156 and a lower portion 158. As shown, intermediatesuspension portion 156 is coupled to the upper and lower portions 154,158 in a four bar linkage fashion allowing the upper and lower portions154, 158 to move relative to each other in dampened fashion. In additionto the items already described on rear suspension 20, rear suspension 20includes a drive system 160 which is input from the propulsion unit 6 byway of a chain; a belt drive system 162 driven by drive system 160through gear casing or chain case 164 and a chain tensioner 166 (FIG. 7)which is moveable into the drive chain for taking up slack. As shownbest in FIG. 8, a disc brake 168 is shown on the backside of drivesystem 160 for braking the snow bike. Furthermore, a bumper system 170is shown which as described herein, prevents a crash between upper andlower portions 154, 158 of the rear suspension 20.

With reference now to FIGS. 12 and 13, upper frame member 22 will bedescribed in greater detail. As shown, upper frame 22 includes twolongitudinal frame members 180 extending lengthwise the entire length ofthe frame member 22. Frame member 180 is interrupted at a front endthereof by way of front cross bar 182 which couples to a front endportion 180 a of frame member 180. Frame portions 180 b extend forwardlyfrom cross-bar 182 and include front coupling members 184 which coupleto a rear section of motorcycle portion 4 (FIG. 1). Frame members 186reinforce frame members 180 b and cross tube 182 in a triangular manner,and while shown as frame tubes, gussets could also be used such as atriangular plate portion welded in place between frame members 180 b andcross tube 182. As shown best in FIG. 13, cross tube 190 couplestogether frame members 180, where an end of cross tube 190 includes athreaded aperture at 190 a. As shown best in FIG. 12 a cross tubeportion 192 is positioned above frame member 180 and includes a threadedaperture at 192 a. As shown in both FIGS. 12 and 13 a cross tube 196 ispositioned rearwardly of cross tube 190 and also couples together framemembers 180. Cross tube 196 includes a threaded aperture at 196 a.Finally, a cross tube 198 is positioned at a rear of frame member 22 andincludes threaded apertures 198 a. Brackets 200 are positionedintermediate cross tubes 182 and 190 to retain chain tensioner 166 andbracket 202 is attached to frame member 180 to attach drive member 160.Upper frame members 210 extend from cross tube 182 rearwardly to crosstube 198 and include reinforcing frame members 212 a, 212 b, and 212 c.

Upper frame portion 154 (FIGS. 9-11) further includes the side panels 26and more particular left side panel 26 a and right side panel 26 bcoupled to the upper frame member 22. As shown best in FIGS. 9 and 11,side panel 26 a is formed of a panel, such as an aluminum or stainlesssteel panel and is configured to couple to the left side of upper framemember 22. In particular, panel 26 includes apertures to receivefasteners 222 a which couples to threaded aperture 192 a (FIG. 12),fastener 222 b to couple threaded fastener 196 a (FIG. 12) and fastener222 c to fasten to threaded aperture 198 a (FIG. 12). As shown in FIG.11, left side panel 26 a further includes apertures 230 a and 230 b forcoupling to the intermediate suspension portion 156 as will be describedherein. As shown in FIG. 11, side panel 26 a further includes apertures230 c and 230 d for receipt therethrough of a driveshaft for drivemember 160 and an aperture for receipt of drive shaft for belt drive162.

With reference now to FIG. 10, right hand side panel 26 b includesapertures for receipt of fasteners 240 a (for coupling with aperture 190a); fastener 240 b (for coupling with threaded aperture 196 a) andfastener 240 c (for coupling with threaded aperture 198 a). Side panel26 b also includes apertures for receipt of fasteners 242 a and 242 bwhich couple with intermediate suspension portion 156 as describedherein. Side panel 26 b also includes a mounting area 244 for couplingbelt drive 162 (FIG. 7).

With reference again to FIG. 11, intermediate suspension 156 iscomprised of a front control arm 250, a front shock absorber at 252, arear control arm 254, and a rear shock absorber at 256. As shown, frontcontrol arm 250 has an upper axle at 260 and a lower axle at 262. Upperaxle 260 includes threaded apertures 260 a and lower axle 262 includesthreaded apertures 262 a. Shock absorber 252 is coupled to upper axle260 at 266 and includes a lower axle at 268 having a threaded aperture268 a. Rear control arm 254 includes an upper axle 270 having a threadedaperture at 270 a and a lower axle 272 and mounted between slide rails24, as described herein.

With reference now to FIG. 14, lower axle assembly 272 includes a spacer274 having threaded apertures at 274 a and axle 276 is slidablyreceivable over spacer 274 and sleeves 278 which are received in openends 280 of axle member 276. As shown, when spacer 274 is receivedthrough sleeves 278 and axle member 276, fasteners 282 a and 282 b maybe received through washers 284, through apertures 286 of slide rails 24such that axle member is rotatable about spacer 274. It should beappreciated that the spacer 274 is slightly longer than the axle 276,allowing the axle 276 to rotate about spacer 274. Axle member 276includes link arms 288 having apertures at 288 a for coupling to rearcontrol arm 254. With reference again to FIG. 11 rear control arm 254includes threaded apertures 254 a at a lower end thereof that may becoupled to apertures 288 a (FIG. 14) with fasteners (not shown). Withrespect still to FIG. 11, rear shock absorber 256 includes a lower axle290 having a threaded aperture at 290 a.

In addition to apertures 286 (FIG. 14) slide rails 24 also includeapertures 300, 302, and 304 (FIG. 11). Thus, and with reference to FIG.11, intermediate suspension portion 156 may be coupled to slide rails 24by way of fasteners through apertures 302 into threaded apertures 268,by fasteners extending through apertures 304 into threaded apertures 262a and fasteners through apertures 300 and into threaded aperture 290 a.

With reference now to FIGS. 15-18, bumper assembly 170 will be describedin greater detail. As shown in FIG. 15, bumper assembly 170 is shownmounted to slide rail 24 above a slot 310 of slide rail 24. Bumperassembly 170 generally includes a plunger at 312, a spring grommet 314and a carrier mount at 316. With reference now to FIG. 16, the bumperassembly 170 is shown exploded away from slide rail 24. As shown,plunger 312 includes a head portion 312 a, a shank portion 312 b and athreaded aperture at 312 c (see FIG. 17). Spring grommet 314 includes apair of resilient bellows 314 a and 314 b coupled to a base portion 314c with an aperture 314 d extending downwardly through spring grommet 314and profiled to receive plunger 312. Carrier mount 316 includes flanges316 a which flank a base portion 318 which includes an aperture 320profiled to receive shank portion 312 b of plunger 312 as describedherein.

To assemble the bumper assembly, plunger 312 is installed throughaperture 314 d of spring grommet 314 with base portion 314 c positionedon base 318 of carrier mount 316. If desired, a thrust washer could bepositioned under the head portion 312 a and above the spring grommet314. Fastener 322 may then be positioned through washer 324 andthreadably received into threaded aperture 312 c of plunger 312.Fasteners 326 are then positioned through apertures 316 b of flanges 316a to couple the bumper assembly to threaded apertures 328 on slide rail24. A cross-sectional view of FIG. 17 shows the bumper assembly asapplied to the side of slide rail 24. As should be appreciated from FIG.17, flanges 316 a are offset asymmetrically with base 318 of mount 316such that the plunger is centered with the slot 310. Thus, as shown inFIG. 18, during a jounce, rear control arm 254 collapses and is alignedwith bumper assembly 170, and in particular with the head portion 312 ofplunger 312, causing spring grommet 314 to compress causing the shankportion 312 b to extend into slot 310.

With reference now to FIGS. 19-30, a second embodiment of a rearsuspension will be described. With reference to FIG. 19 a second rearsuspension is shown at 420 having a frame 422 with a single slide rail424 where carrier rollers 425 flank single side rail 424. Rearsuspension 420 further includes side panels 426, a front control arm428, rear control arm 430, front shock absorber 432 and rear shockabsorber 434. As in the first embodiment, rear suspension 420 includesan input drive 460, belt drive 462 coupled together by way of chain case464, a chain tensioner 466 and a braking system 468. Rear suspension 420further includes a rear bumper assembly 470 as described herein. Withreference now to FIGS. 20-25, chain tensioner 466 will be described ingreater detail.

As shown first in FIGS. 20 and 21, frame 422 includes a front cross barat 482 with elongate extension bars 488 coupled to cross bar 482 andextending generally forward. Sliding mounts 490 are coupled to elongateextension bars 488 and are slidable relative thereto. Chain tensioner466 further includes a locking mechanism at 492 and a chain guide at494.

As shown best in FIG. 22, elongate extension bars 488 include an innerend at 500 which is coupled to the cross bar 482, an inner surface 502which is substantially flat, and an outer surface at 504 havingtriangulated edges at 506. Each of the bars 488 includes apertures at510. As shown in FIGS. 23 and 24, sliding mounts 490 are shown, where inFIG. 23 an inner surface 514 is shown having an integrated channel at516. The channel 516 includes upper and lower surfaces 516 a, an innerflat surface at 516 b, and triangulated surfaces 516 c, which as shouldbe appreciated, align with and cooperate with triangulated surfaces 506on bars 488. Apertures 520 extend through inner surface 516 b and areslotted in a longitudinal direction.

As shown in FIG. 24, sliding mounts 490 include an outside flattenedsurface at 522. A front end 524 of the sliding mount 490 includes acoupler at 526 which is substantially similar to coupler 184 (FIG. 12)to couple the rear suspension 420 to the motorcycle frame. However, inthis embodiment, the chain is tightened by providing longitudinalflexibility in the position of the rear suspension relative to themotorcycle frame. In that regard, fasteners 528 (FIG. 22) are providedwhich are receivable through slotted apertures 520 and into threadedengagement with threaded apertures 510. The triangulated surfaces 506,516 c allows vertical alignment of the sliding mounts relative to thebars 488 and positioning fasteners 528 into threaded engagement withthreaded apertures 510 allows sliding mounts 490 to be moveablelongitudinally to the extent of the slotted apertures 520, as describedfurther herein.

With reference now to FIG. 22, locking mechanism 492 will be described.As shown in FIG. 22, cross bar 482 includes an aperture at 482 a and hasan undercut portion at 482 b. The locking mechanism is comprised ofO-rings 530, a rod 532, a locking cam 534 and fasteners 536, 538. Rod532 has an aperture at 532 a and a flattened surface at 532 b. Lockingcam has an eccentric lobe at 534 a and an aperture at 534 b havingflattened inner surfaces at 534 c. Fastener 536 has flattened surfacesat 536 a.

Thus, once the rear suspension 420 is positioned on the motorcycleframe, the rear suspension can be moved rearwardly to tighten the chainwhereupon the threaded fasteners 528 can be tightened to the position toretain sliding mounts 490 relative to bars 488. At this point, theO-rings 530 can be received over each end of the cross bar 482 and bereceived in the undercut portion 482 b. Rod 532 is then received intoaperture 482 a and locking cams 534 are positioned over the ends of rod532 aligning the flattened surfaces 532 b, 534 c. Fasteners 536 may bereceived in aperture 534 b and fasteners 538 may be brought intothreaded engagement with threaded apertures 532 a of rod 532. Twowrenches may now be used to bring the locking mechanism into a fulllocking condition, for example, a box wrench or adjustable wrench may beused with fastener 536 whereby a torque may be applied to the lockingcam 534 to position it against the sliding mount 490. At the same time,a second wrench such as an allen wrench may be used to tighten thefasteners 538 to bring the locking mechanism in a fully locked position.

This is shown in diagrammatic form in FIGS. 25A and 25B where in theposition of FIG. 25A sliding lock 490 is moved to the full left positioninto the direction of arrow A and locking cam 534 is rotated in thecounter-clockwise direction until it abuts the end of sliding 490. Inthis position, a distance between the center of the mounting member 526and the fastener 538 is a distance D₁. With reference now to FIG. 25b ,the sliding mount 490 is moved to the fully right hand position in thedirection of arrow B and locking cam 534 is rotated in a clockwiseposition to accommodate the lateral movement of the locking mount 490.The corresponding distance in this position is D₂, where D₁ is greaterthan D₂.

With reference now to FIGS. 26-39, bumper assembly 470 will be describedin greater detail. As opposed to the first embodiment of rear suspension20 where the bumper assembly 170 was provided on the slide rail, and thecontrol arm rotated into the bumper assembly, this embodiment is exactlythe opposite; that is, the bumper assembly 470 is mounted to the controlarm 430 and the movement of the control arm downwardly provides contactbetween the slide rail 424 and the bumper assembly 470.

As shown best in FIGS. 27-29, the control arm 430 includes two armmembers 550 (FIG. 29) with a lower coupler 552 which mounts to a linkassembly 554 (FIG. 26) and an upper coupler at 560 which couples to sidepanels 426 (FIG. 26). Rear control arm 430 further includes a mount orbracket at 562 having a base portion 564 with an aperture 566 extendingtherethrough. Bumper assembly 470 is substantially similar to bumperassembly 170 including a plunger 582, spring grommet 584, fastener 592and washer 594. The fully assembled position of the bumper assembly 470is shown in FIG. 27 where plunger 582 is positioned through springgrommet 584 with fastener and washer positioned against base portion 564and fastener 592 threaded into threaded engagement with threadedaperture 590 (FIG. 28).

As shown in FIG. 30, in this embodiment, when rear control arm 430rotates in the direction downwardly in the direction of arrow C, plunger528 contacts an upper edge 424 a of slide rail 424. The extent of travelupwardly of plunger 528 is shown by the difference between the plunger528 in solid lines versus plunger 528 in phantom lines.

With reference now to FIGS. 31-40, a third embodiment of a rearsuspension will be described. With reference to FIG. 31 a third rearsuspension is shown at 620 having a frame 622, slide rails 624, toptunnel portion 625, side panels 626, a front control arm 628, rearcontrol arm 630, front shock absorber 632 and rear shock absorber 634. Aprogressive rate linkage 635 is coupled between the rear control arm andthe frame as described herein. As in the first embodiment, rearsuspension 620 includes an input drive 660, belt drive 662 coupledtogether by way of chain case 664, and a chain tensioner 666. Withreference now to FIGS. 32-34, frame 622, side panels 624 and top tunnel625 will be described in greater detail.

With reference first to FIGS. 33 and 34, frame 622 is shown as a unibodyconstruction having an elongate frame member or spine 700 with agenerally rectangular cross-section. Spine 700 has side walls 702 with afront-end at 704, a rear end at 706, a lower wall 708 and a top wall710. Frame member 700 could be manufactured from one or multiple sheetsof rigid material such as aluminum or steel where portions of the sheetare stamped and formed into the box-shaped configuration shown in FIGS.33 and 34 and bonded together such as by welding or industrial adhesivesand the like. Frame member 700 could also be manufactured from acasting, such as an aluminum casting.

Side walls 702 include an enlarged aperture 720 extending therethroughencircled by apertures 722. Apertures 720 is profiled to receive inputdrive 660 (FIG. 31) and attached thereto by way of fasteners throughapertures 722. Frame 622 further includes four cross bars; a first crossbar 726, a second cross bar 728, a third cross bar 730, and a fourthcross bar 732. Each of the cross bars 728-732 include threaded apertures728 a, 730 a, and 732 a respectively.

As shown best in FIG. 33, a portion of chain tensioner 666 (FIG. 31) isdefined by a unitary member 740 which may be a casting or forging ofmetal or aluminum which includes a body portion at 742 having twocoupling members 744 and 746 encircling the cross bars 726 and 728. Asshown, a portion of cross bar 728 protrudes beyond the coupler 744whereas coupler 746 encapsulates an end portion of cross bar 726.Couplers 744 and 746 may be coupled to their corresponding cross bars728, 726 by such means as industrial adhesives, fasteners or welding.Extension bars 750 extend forwardly from couplers 746 and includeelongated apertures at 752. Chain tensioner 666 further includes slidemounts 756 (FIG. 31) having apertures at 758. Chain tensioner 666operates in substantially the same way as chain tensioner 466 with theonly difference being in the location of the slotted apertures 752.

With reference again to FIG. 32, right side panel 626 include apertures626 a, 626 b and 626 c which align with corresponding apertures 728 a,730 a and 732 a (FIG. 34). Left side panel 626 includes a large aperture762 to receive the chaincase 664, and apertures 730 a and 732 a. Rightside panel 626 includes an aperture 764 for receiving an opposite end ofbelt drive 662 (FIG. 31). Each of the side panels 626 also include pairsof apertures 770 a, 770 b and 772 a, 772 b for coupling of thesuspension as provided herein. Side panels 626 also include a pluralityof apertures 774 for coupling of the top panel or tunnel portion 625.

As shown in FIG. 32, top panel 625 includes a stamped and formed pieceof material such as aluminum or steel with a generally flat portion at780 having folded flaps 782 at the marginal edges thereof. Inclinedportions at 784 lead into top panel portions 786 having a slot 788extending therebetween. The marginal edges 782 includes a plurality ofapertures at 782 a for coupling with the plurality of apertures 774 inside panels 626 to retain the top panel 625 to the side panels 626. Atthe same time the slot 788 allows the top panel portions 786 to flankthe frame portion 622 as best shown in FIG. 31.

With reference now to FIGS. 35-38, progressive rate linkage 635 will bedescribed in greater detail. With reference first to FIG. 38, rearcontrol arm 630 will be described having a lower coupler 790 havingopenings at 792 with frame members 794 extending upwardly and forwardlyterminating in couplers at 796 having openings at 798. Midway up framemembers 794 are two bracket members 800 having a portion 802 mounted tothe frame member 794 and a portion 804 depending downwardly therefromhaving a front aperture at 806 and a rear aperture at 808.

The mounting of rear control arm 630 to slide rails 624 is done by wayof a link assembly 810 having a tubular portion 812 having threadedapertures at 812 a and an upstanding bracket at 812 b having aperturesat 812 c. An axle 816 is provided having threaded apertures at 816 a.Thus, coupler 790 is coupled to brackets 812 b by positioning axle 816through coupler 790, and by aligning apertures 816 a and 812 c together,whereupon fasteners 818 and washers 820 can couple control arm 630 tolink assembly 810. That combination may be coupled to the slide rails624 by positioning a fastener (not shown) through apertures 822 a (FIG.35) and threadably engaging threaded apertures 812 a.

A triangular link assembly 830 is shown in FIG. 35 coupled to bracket800. As shown in FIG. 38, triangular link assembly 830 includes atriangular link 832, an adjustable link 834 and an axle at 836. As shownbest in FIG. 38, triangular link 832 has three pivotal points at 832 a,832 b and at enlarged opening 832 c. Adjustable link 834 includes ashank portion at 834 a and a coupler at 834 b. Shank portion 834 aincludes a threaded aperture at 834 c and coupler 834 b includes anopening at 834 d. Adjustable link 834 also includes a ball joint portion834 e having a ball joint with an aperture at 834 f Adjustable link isassembled by threading nut 834 g onto threaded portion 834 e and thenthreading threaded portion 834 e into threaded aperture 834 c. It shouldbe appreciated that the linear length of the adjustable link 834 may beadjusted by the location of the lock nut 834 g relative to the shankportion 834 a. Adjustable link 834 is now positioned over axle 836 withbushings 838 positioned in apertures 834 d. Couplers 840 may now beslidably received over axle member 836 and against coupler 834 b andlocked in place.

Axle 836 may be coupled to slide rails 624 by inserting a fastener (notshown) through apertures 822 b (FIG. 35) and aligning them with theapertures 836 a (FIG. 38). It should be appreciated that ball jointopening 834 f is coupled to triangular link aperture 832 a by way of afastener 832 d. It should also be appreciated that aperture 832 c oftriangular link 832 is coupled to aperture 808 of bracket 800. To thatend, aperture 832 c receives bearings 850 a, spacer 852 a, grommets 854a and washers 856 a. That assembly is then positioned relative toaperture 808 of bracket 800, whereby fasteners 858 a may be receivedthrough apertures 808 and threaded into spacer 852 a.

Linkage 635 further includes a link 870 having a coupler 872 and 874.Coupler 872 may be coupled to aperture 832 b of triangular link 832 bypositioning bearings 850 b in each of the couplers 872 and 874 followedby spacers 852 b and washers 856 b. A fastener 858 b may then bepositioned into aperture 832 b through the spacer 852 b and coupler 872and into a threaded aperture on the opposite side of the triangular link832.

Linkage 635 further includes a link 880 having a lower coupler at 882having an aperture at 882 a and two link arms 884 having apertures at886 and 888. Link 870 is coupled to link 880 by way of a fastener 858 bextending through aperture 888 of link 880 and through bearing 850 b,spacer 852 b, washers 856 b and coupling opening 874 of link 870.Meanwhile, link 880 is coupled to bracket 800 by positioning bearings850 c, spacer 852 c, grommet 854 c and washer 856 c in aperture 882 a,whereupon a fastener 858 c may be received through opening 882 a of link880 and through aperture 806 of bracket 800. This couples both thetriangular link 832 and the link 880 to the bracket 800, with the link870 coupled between the triangular link 830 and link 880.

Finally, shock absorber 634 may be installed in the assembly. Shockabsorber 634 includes a coupling at 634 a which couples to aperture 886of link 880. Upper end of shock 634 includes a coupling 634 b coupled toan axle member 900 (FIG. 36) which is shown in FIG. 35 as coupled to aninside of side panels 626. Namely axle 900 includes brackets 902 havingapertures at 902 a which may receive fasteners therethrough and intoside panel 626.

In operation, and with reference to FIGS. 36 and 37, when the controlarm 630 begins to rotate in a downward sense, triangular link 832 willrotate about bracket 800 causing link 870 to push the link 880 forward.As link 870 is coupled to a midpoint of link 880, the shock iscompressed or stroked at a greater rate than it would with a directconnection. This is also shown diagrammatically in FIGS. 39 and 40 wherecontrol arm is moved from the position shown in FIG. 39 to a collapsedposition shown in FIG. 40. This movement causes triangular link 832 torotate in the clockwise sense (as viewed in FIGS. 39 and 40) whichcauses link 870 to push link 880 forward and due to the connection ofthe shock 634 to the upper end of link 880, the shock is stroked at agreater rate and at a progressive rate.

Alternatively, and with respect to FIG. 36A, adjustable link 834 couldbe coupled directly to the tubular portion 812 of link assembly 810.

With reference now to FIGS. 41-43, the application of the chain case 664to the belt drive 662 will be described in greater detail. As shown bestin FIG. 41, chain case 664 includes a drive portion 920 and a cover 922.Drive portion 920 includes housing 924 having an outer flange 926 thatoverlaps opening 762 and a reduced profile portion 930 (FIG. 43) whichprotrudes through opening 762.

As shown best in FIG. 42, input drive 660 includes a sprocket 934 havingan output coupler 936 for coupling to input driveshaft 938 of chain case922. A drive sprocket is shown as coupling to a sprocket 940 which isdriven by a belt or chain. A driven sprocket 942 is coupled to the drivesprocket 940 which in turn drives belt drive 662 by way of a drive shaft944 to sprockets 946. An idler roller 950 is shown having a tensioner952 for tensioning the chain or belt. Drive shaft has a shaft coupling954 which couples to a bearing 956 mounted on an inside of side panel626.

Due to the compactness of the suspension frame 622, the volume of spacebeneath the frame 622 is open, which allows the belt drive 662 asassembled to the drive portion 920 (as shown in FIG. 42) to be installedthrough the opening 762 and under the frame 622, to a position whereshaft coupling 954 couples to the bearing 956. Drive portion 920 may becoupled to side panel 626, by way of a fastener 960 positioned throughaperture 962 and threadably engaged with threaded aperture 728 a; aswell as with fasteners 964 (such as rivets) positioned through aperture968 and engaged with aperture 762 a.

With reference now to FIG. 1, the location of the drive axis of the beltdrive is shown as Ai, where a vertical distance from the top of the footpeg 38 to drive axis distance Ai is shown as Y, and a horizontaldistance from the center of the foot peg 38 to drive axis Ai is shown asX. An attempt has been made in the embodiments herein to move the driveaxis Ai up out of the snow of the snow as much as possible for deep snowapplications. Thus for the embodiments of FIGS. 7 and 31, the dimensionX is in the range of 6.222″ to 7.922″ and more specifically in the rangeof 7.000″-7.500″. In the embodiment shown X=7.422″. For the embodimentsof FIGS. 7 and 31, the dimension Y is in the range of 3.400″-5.400″ andmore specifically in the range of 3.750″-4.500″. In the embodiment shownY=3.900″.

Thus, as the foot peg 38 locates the rider, an attempt has been made tokeep the distance Y to a minimum. As the foot peg 38 tends to dictatethe location of the rider, the distance X was selected to center thedriver's mass with the mass of the vehicle.

Although a chain case is shown in the embodiments of FIGS. 7, 19 and 31,a belt drive could be used such as that shown in U.S. Pat. No.8,919,477, the subject matter of which is disclosed herein by reference.This belt drive is designed to not require a tensioning device, suchthat the belt drive of U.S. Pat. No. 8,919,477 could replace any of theaforementioned chain cases 164, 464, and/or 664.

With reference now to FIGS. 44-48C, a second embodiment of the frontsuspension assembly will be described. As shown best in FIGS. 44-46,front suspension assembly 216 is shown, but in this embodiment, thesuspension 216 is coupled to two skis 218 (Left ski 218L and right ski218R). Front suspension assembly 216 generally includes a spindle body240, and a lower linkage portion 242. The front suspension 216 wouldalso include a mounting portion similar to that as shown at 44 in FIG.3, for connection to the forks 12. In this embodiment, front suspensionassembly 216 includes an independent suspension for each one of the skis218, as discussed herein.

As shown best in FIGS. 47-48C, spindle body 240 is generally comprisedof two plates 250 and 252 where each plate includes a plurality ofapertures. Namely, plate 250 includes apertures 250 a-250 c togetherwith enlarged apertures at 250 d-250 f. Likewise, plate 252 includesapertures 252 a-252 c and enlarged apertures at 252 d-252 f Spindle body240 also includes a plurality of spacers to space the plates 250 and 252apart, namely spacers 254 a, 254 b, 254 c, 254 e and 254 f. An enlargedspacer is provided at 254 d. It should be noted that each of the spacers254 e and 254 f are somewhat spool-shaped having an enlarged headportion 256 (FIG. 48A) at each end as well as threaded openings 258 ateach end (FIG. 48A). Enlarged head portion 256 defines reduced diameterportion 256 a and shoulder 256 b (FIG. 48A). Enlarged spacer 254 d isembossed at each end to define a reduced diameter section 260 definingshoulders 262 (FIG. 48A).

Thus, the spindle body 240 may be preassembled by placing the spacers254 d, 254 e and 254 f between the plates 250 and 252. This is done byplacing the reduced diameter portions 260 of spacer 254 d intorespective apertures 250 d and 252 d; by placing the reduced diameterportions 256 a of spacer 254 e into respective apertures 250 e and 252e; and by placing the reduced diameter portions 256 a of spacer 254 finto respective apertures 250 f and 252 f (FIGS. 47 and 48A). Thispositions the reduced diameter portions 260 through their correspondingapertures as shown in FIG. 44. This also positions the reduced diameterportions 256 a through their corresponding apertures (250 e, 250 f; 252f, 252 f) as the shoulders 256 b abut the plates 250, 252.

Spacers 254 a and 254 c are also installed by aligning them withcorresponding apertures 250 a, 252 a and 250 c, 252 c. Fasteners maythen be positioned against plates 250 and 252 to retain the two platestogether and coupled to the spacers. Namely, fastener 270 a (FIG. 48A)may be aligned with aperture 250 a of plate 250 and brought intothreaded engagement with threaded aperture of spacer 254 a. Likewise,fastener 270 a may be aligned with aperture 252 a of plate 252 (FIG. 47)and received into the threaded aperture of spacer 254 a. Also fastener270 c (FIG. 48A) may be aligned with aperture 250 c of plate 250 andbrought into threaded engagement with threaded aperture of spacer 254 c.Likewise, fastener 270 c may be aligned with aperture 252 c of plate 252(FIG. 47) and received into the threaded aperture of spacer 254 c.

With reference still to FIGS. 47-48C, the link assembly 242 will bedescribed in greater detail. As shown best in FIG. 47, link assembly 242includes two independent suspensions, namely a right suspension 264 anda left suspension 266. Right suspension 264 includes a front link orcontrol arm 300 and a rear link or control arm 302. As shown best inFIG. 48A, control arm 300 includes an upper coupling 300 a and a lowercoupling at 300 b. Likewise, control arm 302 includes an upper couplingat 302 a and a lower coupling at 302 b. Left suspension 266 includes afront link or control arm 304 and a rear link or control arm 306.Control arm 304 (FIG. 47) includes an upper coupling 304 a and a lowercoupling at 304 b (FIG. 48B). Likewise, control arm 306 includes anupper coupling at 306 a and a lower coupling at 306 b (FIG. 48B).

Each of the upper couplings 300 a and 302 a receive sleeves 305 (FIG.48A) which are profiled to be received in the couplings 300 a, 302 a.Couplings 300 a and 302 a of control arms 300 and 302 are thenpositioned over the reduced diameter portions 256 a of spacers 254 e and254 f which protrude through apertures 250 e 250 f Thus, control arms300 and 302 of right suspension 264 may be aligned with respectiveapertures 250 e and 250 f, (FIG. 48A) and fastened to the spindleassembly by way of fasteners and washers 270 e, 272 e and 270 f, 272 fIn a like manner, control arms 304 and 306 of left suspension 266 alsoreceive sleeves 305 (FIG. 47) and are then positioned over the reduceddiameter portions 256 a of spacers 254 e and 254 f which protrudethrough apertures 252 e, 252 f of plate 252 (FIG. 47). Thus, controlarms 304 and 306 of left suspension 266 may be aligned with respectiveapertures 252 e and 252 f, (FIG. 47) and fastened to the spindleassembly by way of fasteners and washers 270 e, 272 e and 270 f, 272 f.

With reference again to FIG. 48A, linkage assembly 242 further includesa knuckle 310 having a front pivot coupling 310 a having a threadedaperture at 310 b and a rear pivot coupling 310 c having a threadedaperture 310 d. Spacer 311 and sleeves 312 may be received in lowercouplings 300 b, 302 b of control arms 300, 302 whereupon lowercouplings 300 b, 302 b may be received in front and rear pivot coupling310 a, 310 c and fasteners 314 may be received in alignment withthreaded apertures 310 b, 310 d to couple control arms 300, 302 with theknuckle 310.

Finally, with reference to FIG. 48C, linkage 242 further includes shockabsorbers 324, 325 having lower couplings at aperture 324 a, 325 a andupper couplings at 324 b, 325 b. Split sleeves 326, 327 include reduceddiameter portions 326 a, 327 a. Split sleeves 326 may be positioned withreduced diameter portions 326 a in apertures 324 b of shock absorber324. Likewise, split sleeves 327 may be positioned with reduced diameterportions 327 a in apertures 325 b of shock absorber 325. The shockabsorbers 324, 325 may then be coupled to the spindle assembly by way ofspacer 254 b. That is, spacer 254 b is positioned through sleeves 326,327 with spacer 254 b aligned with apertures 250 b, 252 b. Fasteners 272b are then inserted through apertures 250 b, 252 b and into threadedapertures of spacer 254 b. This pivotally couples the two shockabsorbers 324 and 325 to the spindle 240.

The lower apertures 324 a, 325 a of shocks 324, 325 may then be coupledto control arms 302, 306 as shown in FIG. 48C. A first sleeve 330 ispositioned with a reduced diameter portion 330 a within aperture 324 aof shock 324. The sleeve 330 and the shock aperture 324 a are thenaligned with aperture 302 d on boss 302 e whereupon fastener 340 may bereceived through sleeve 330 and into aperture 302 d. Likewise, a secondsleeve 332 is positioned with a reduced diameter portion 332 a withinaperture 325 a. The sleeve 332 and the shock aperture 325 a are thenaligned with an aperture (not seen in FIG. 48C) on boss 306 e whereuponfastener 342 may be received through sleeve 332 and into the aperture.

Thus, the entire assembled second suspension system 216 is shown inFIGS. 44-46 where knuckle 310 is shown as providing an aperture 310 e(FIG. 48B) for coupling to ski 218 as shown. That is, ski 218 includesski rails 218 a whereby a pin 218 b may be received through the railsand into aperture 310 e for retaining ski 218 to the second suspensionsystem 216.

Thus, in operation and with reference to FIGS. 44-46, skis 218R and 218Lare shown in a fully down position as the right and left suspensions areshown in their respective extended positions. However, as thesuspensions 264, 266 are independent, either ski 218R or 218L may moverelative to the other. For example, as shown FIGS. 48-53, the leftsuspension 266 is shown in a collapsed position, whereas the rightsuspension 264 is shown in a fully extended position. This can be seenin FIG. 50 where the shock absorber 324 is shown in its original andfully extended position, whereas shock absorber 325 is shown fullycollapsed. This can also be seen in the comparison of FIGS. 52 and 53,where in FIG. 52, the control arms 304 and 306 are shown in theircollapsed position, whereas in FIG. 53, the control arms 300 and 302 areshown in their fully extended position. As in the previous embodiment,and as best shown in FIG. 52, when control arms control arms 304 and 306are collapsed with the shock absorber 324 in a stroked position, theleft ski 218L is lifted up relative to right ski 218R. It also movesrearwardly, as in the previous embodiment, having the advantages aspreviously enumerated. In addition ski 218L is rotated slightly in theclockwise direction, as viewed in FIG. 52.

In the second embodiment, the independent movement of the skis relativeto each other has its advantages. First, as there are two skis 218, theskis may provide a wider base than a single ski providing betterstability and steering capability. Second, as the skis 218 may moverelative to each other, one of the skis (for example left ski 218L inFIGS. 54-55) may be lifted to pass over an object 400, which providesgreater stability to the snow bike as the right ski 218R maintainscontact with the ground. This provides the ability for one of the skisto be lifted up and over the object without losing control of the snowbike or without a large jolt to the front end of the snow bike. Third,and with reference to FIG. 56, when the snow bike is traversing a sideslope, the skis can track with the slope to provide two levels of skicontact with the slope for better stability. Finally, due to the fourbar linkage design the amount of ski trail may be adjusted versus thesuspension ravel, where ski trail equals the length of the skag or therunner is behind the ski pivot bolt. Thus the ski trail can be adjustedthroughout the stroke of the suspension and that can all be dependent ofthe four bar linkage.

In another embodiment, the two shocks can be adjusted to act differentlyfrom each other. For example, a crossover tube 420 (FIG. 49) between theshocks causes the skis to actuate oppositely. That is, when one shock isstroked, it pushes the other down, as the dampening medium is pushedfrom the stroked shock to the extending shock. This also helps insteering. The crossover tube 420 connects the air flow shocks such thatwhen you lean left, the inside ski lifts up easier and then appliespressure to the outside ski because it's equalizing pressure between thetwo shocks so it's less rising rate on the inside ski and more of arising rate on the outside ski which helps it maneuver the corner betterthan if the two shocks weren't connected between each other.

In another embodiment, a connecting rod or sway bar could be coupledbetween the skis to couple the two shock absorbers together.

While this invention has been described as having an exemplary design,the present invention may be further modified within the spirit andscope of this disclosure. This application is therefore intended tocover any variations, uses, or adaptations of the invention using itsgeneral principles. Further, this application is intended to cover suchdepartures from the present disclosure as come within known or customarypractice in the art to which this invention pertains.

What is claimed is:
 1. A snow vehicle comprising: a vehicle frame; apropulsion unit coupled to the frame; at least one front ski; a steeringmechanism coupled to the frame; a first front suspension coupled to theframe; a rear suspension coupled to the frame, the rear suspensioncomprising: at least one slide rail; at least one control arm coupledbetween the slide rail and the frame; at least linear force elementcoupled between the slide rail and the frame; and at least one carrierroller coupled to the at least one slide rail and the frame; a bumperassembly preventing bottoming out of the rear suspension; and a drivesystem comprising a drive track slidably guided by the at least oneslide rail and drivably coupled to the propulsion unit.
 2. The snowvehicle of claim 1, wherein the rear suspension comprises a suspensionframe.
 3. The snow vehicle of claim 2, wherein the vehicle frame is amotorcycle frame and the suspension frame is coupled to the motorcycleframe.
 4. The snow vehicle of claim 1, wherein the bumper assembly iscoupled to the rear suspension and positioned to prevent contact of theat least control arm and a remaining portion of the rear suspension. 5.The rear suspension of claim 4, wherein the bumper assembly is mountedintermediate the at least at least control arm and the at least oneslide rail, and the bumper assembly resiliently contracts during jounce.6. The rear suspension of claim 5, wherein the bumper assembly comprisesa spring grommet and a carrier mount.
 7. The rear suspension of claim 6,wherein the bumper assembly further comprises a plunger extendingthrough the spring grommet.
 8. The rear suspension of claim 7, whereinthe plunger comprises a head portion and a shank portion.
 9. The rearsuspension of claim 8, wherein the spring grommet includes an apertureextending downwardly therethrough and profiled to receive the plunger.10. The rear suspension of claim 6, wherein the spring grommet includesa pair of resilient bellows coupled to a base portion.
 11. The rearsuspension of claim 10, wherein the carrier mount includes flanges whichflank a base portion of the carrier mount.
 12. The rear suspension ofclaim 5, wherein the bumper assembly is mounted on the at least oneslide rail and the at least control arm contacts the bumper assemblyduring jounce.
 13. The rear suspension of claim 12, comprising two sliderails and two control arms wherein the bumper assembly is mounted on theslide rails and the control arms contact the bumper assembly duringjounce.
 14. The rear suspension of claim 12, wherein the at least oneslide rail is slotted at a top edge thereof, and the bumper assembly ismounted over the slot.
 15. The rear suspension of claim 14, wherein thebumper assembly comprises a plunger which aligns with the slotted sliderail, and the plunger moves into the slot during jounce.
 16. The rearsuspension of claim 5, wherein the bumper assembly is mounted on the atleast control arm and the bumper assembly contacts the at least oneslide rail during jounce.
 17. The rear suspension of claim 16, whereinthe at least control arm comprises a bracket which mounts the bumperassembly thereto.
 18. A rear suspension for a snow vehicle, comprising:at least one slide rail; a frame; at least one control arm coupledbetween the slide rail and the frame; at least linear force elementcoupled between the slide rail and the frame; at least one carrierroller coupled to one of the slide rail and the frame; a drive systemcomprising a drive track slidably guided by the at least one slide railand drivably coupled to the propulsion unit; and a bumper assemblycoupled to the rear suspension and positioned to prevent contact of theat least control arm and a remaining portion of the rear suspension. 19.The rear suspension of claim 18, wherein the bumper assembly is mountedintermediate the at least at least control arm and the at least oneslide rail, and the bumper assembly resiliently contracts during jounce.20. The rear suspension of claim 19, wherein the bumper assembly ismounted on the at least one slide rail and the at least control armcontacts the bumper assembly during jounce.
 21. The rear suspension ofclaim 20, comprising two slide rails and two control arms wherein thebumper assembly is mounted on the at least one slide rail and thecontrol arms contact the bumper assembly during jounce.
 22. The rearsuspension of claim 20, wherein the at least one slide rail is slottedat a top edge thereof, and the bumper assembly is mounted over the slot.23. The rear suspension of claim 22, wherein the bumper assemblycomprises a plunger which aligns with the slotted slide rail, and theplunger moves into the slot during jounce.
 24. The rear suspension ofclaim 19, wherein the bumper assembly is mounted on the at least atleast control arm and the bumper assembly contacts the at least oneslide rail during jounce.